Bahraini women shout anti-government slogans and gesture at a low-flying police helicopter (unseen) in Sitra, Bahrain, Wednesday, Aug. 31, 2011, during a demonstration shortly after the death of 14-year-old Ali Jawad Ahmad. One of the women is holding a picture of "the martyr, Hajj Ali Khudhair," who died in past political unrest. Bahraini security forces clashed with anti-government protesters after Wednesday morning prayers, and the teenager died in Sitra after being hit by a police tear gas canisters, human rights activists said. (AP Photo/Hasan Jamali)— AP

Bahraini women shout anti-government slogans and gesture at a low-flying police helicopter (unseen) in Sitra, Bahrain, Wednesday, Aug. 31, 2011, during a demonstration shortly after the death of 14-year-old Ali Jawad Ahmad. One of the women is holding a picture of "the martyr, Hajj Ali Khudhair," who died in past political unrest. Bahraini security forces clashed with anti-government protesters after Wednesday morning prayers, and the teenager died in Sitra after being hit by a police tear gas canisters, human rights activists said. (AP Photo/Hasan Jamali)
/ AP

A masked Bahraini anti-government protester gestures and holds a picture of a jailed Shiite cleric up toward a low-flying police helicopter (unseen) in Sitra, Bahrain, oWednesday, Aug. 31, 2011, during a demonstration shortly after the death of 14-year-old Ali Jawad Ahmad. Bahraini security forces clashed with anti-government protesters after Wednesday morning prayers, and the teenager died in Sitra after being hit by a police tear gas canisters, human rights activists said. (AP Photo/Hasan Jamali)— AP

A masked Bahraini anti-government protester gestures and holds a picture of a jailed Shiite cleric up toward a low-flying police helicopter (unseen) in Sitra, Bahrain, oWednesday, Aug. 31, 2011, during a demonstration shortly after the death of 14-year-old Ali Jawad Ahmad. Bahraini security forces clashed with anti-government protesters after Wednesday morning prayers, and the teenager died in Sitra after being hit by a police tear gas canisters, human rights activists said. (AP Photo/Hasan Jamali)
/ AP

A Bahraini man's shadow falls on the blood-stained sidewalk he is photographing in Sitra, Bahrain, on Wednesday, Aug. 31, 2011, where a relative of 14-year-old Ali Jawad Ahmad said the youth was shot. Bahraini security forces clashed with anti-government protesters after Wednesday morning prayers, and the teen-ager died in Sitra after being hit by a police tear gas canisters, human rights activists said. (AP Photo/Hasan Jamali)— AP

A Bahraini man's shadow falls on the blood-stained sidewalk he is photographing in Sitra, Bahrain, on Wednesday, Aug. 31, 2011, where a relative of 14-year-old Ali Jawad Ahmad said the youth was shot. Bahraini security forces clashed with anti-government protesters after Wednesday morning prayers, and the teen-ager died in Sitra after being hit by a police tear gas canisters, human rights activists said. (AP Photo/Hasan Jamali)
/ AP

DUBAI, United Arab Emirates 
It's become a nightly duel in Bahrain: Security forces and anti-government protesters waging hit-and-run clashes in one of the simmering conflicts of the Arab Spring.

So far, the skirmishes have failed to gel into another serious challenge to the Gulf nation's Western-backed monarchy after crushing a reform rebellion months ago. But there are sudden signs that Shiite-led demonstrators could be poised to raise the stakes again on the strategic island, which is home to the U.S. Navy's 5th Fleet.

Hundreds of demonstrators Wednesday made their boldest attempt in months to reclaim control of a central square in the capital Manama, which was the symbolic hub of the protest movement after it began in February. Riot police used buses to block roads and flooded streets with tear gas to drive back the marchers before dawn.

Hours later, mourners gathered in a Shiite village in another part of Bahrain for a 14-year-old boy they claim was killed by security forces. Clashes flared until early Thursday across the oil hub area of Sitra before the boy's burial.

"Down with the regime," chanted some of hundreds of people in the funeral procession. "More protests."

Some waved the flag of the Libyan rebels, who are closing in on the remnants of Moammar Gadhafi's government.

Bahrain remains the outlier of the Arab revolts.

Its Sunni rulers have managed to hold their ground - and even tighten their grip with military help from neighboring Saudi Arabia - against majority Shiites demanding a greater political voice. Washington and Western allies have denounced the punishing crackdowns, but been mild when it comes to Bahrain's ruling dynasty. The possible risks from a harder line appear too great. They include jeopardizing key Arab military relationships on Iran's doorstep.

Washington's Gulf Arab allies argue any gains for Bahrain's Shiites could open the door for influence by Iran's Shiite regime.

Bahrain's Shiite leaders strongly deny any links to Iran. They note that their fight for greater rights goes back decades - and is now re-energized by the pro-democracy wave across the Arab world.

In July, the Shiite political bloc walked out of government-led reconciliation talks, claiming they failed to address key demands such as ending the monarchy's ability to hand-pick the government. Shiites also appear ready to boycott parliament elections on Sept. 24 - an act that state media has called treason.

Shiites account for about 70 percent of Bahrain's 525,000 citizens, but claim they face systematic discrimination such as being barred from top political and security posts. Last week, Bahrain's most senior Shiite cleric, Sheik Isa Qassim, told worshippers that the country's rulers can either embrace reforms or risk the same fate as Libya's Gadhafi.

"Can't they learn from the fall of dictatorships and see what happens to those who denied their people basic rights?" Qassim said as police helicopters patrolled over his mosque. "We now see what happens to the Libyan dictator, just as what happened to Tunisian and Egyptian despots."

At least 32 people have been killed since the protests began more than six months ago. Activists claim Ali Jawad Ahmad, the 14-year-old buried Wednesday, should be added to the tally.